The main difference between SharedFlow and StateFlow is how they work with data emission and state management in Kotlin's flow API.

1. StateFlow is used for holding a single updatable state. It always have a current value, and if you update the value, it replace the old one. StateFlow is like LiveData in Android, it always hold the latest state and emit that when new subscriber come.

2. SharedFlow is more like a broadcast mechanism. It don't hold any value. It is used to emit event or multiple values to many subscribers. SharedFlow is hot flow, so it keeps running even if there is no collector. And you can config it with replay, buffer size etc.

For example:

• Use StateFlow - when you need to hold UI state, like screen data, because it always have latest value.
• Use SharedFlow for one-time event, like showing Toast or navigation action.